KCNQ1 Variant A300G

Summary of observed carriers, functional annotations, and structural context for KCNQ1 A300G. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

32%

3/10 effective observations

Total carriers

0

0 LQT1 · 0 unaffected

Functional studies

0

Publications with functional data

A300G has not been reported in gnomAD. This residue resides in a Mild_Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 3 individuals with LQT1 and 7 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-3.89 0.951 -1 0.788 33

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. BLAST-PSSM reflects evolutionary conservation; more negative values indicate rarer substitutions. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT1 Other Disease
Literature, cohort, and gnomAD – 0 0 0 –
Variant features alone – 15 7 3 –

Totals may differ from individual publications due to duplicate patients removed during curation.

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD.

Previously observed variants near A300G.
Neighbour residue Distance (Å) Observed variants
300 0 A300T, A300S,
301 4
298 4 S298I, S298N,
303 5 L303P,
299 5
302 5 A302V, A302E, A302T,
141 7 V141M,
304 7 W304R, W304R,
297 8 G297S, G297D, G297R,
145 8
144 8 T144A,
281 8 Y281C
277 9 S277L, S277del, S277P, S277W,
323 9
142 9
327 10 T327A, T327S, T327S,
140 10 S140G, S140R, S140R, S140R,
307 11 V307L, V307L,
138 11
274 11 I274V,
143 11 S143F, S143P, S143Y,
273 11 L273F, L273V, L273R,
231 12 R231C, R231H, R231S,
137 12 L137F, L137P,
294 12 V294M,
148 12
278 12 Y278H,
285 12
147 13 Q147R,
326 13
146 13 E146K, E146G, E146Q,
293 14 R293C, R293H,
139 14
320 14 P320H, P320A, P320S,
235 14 I235N,
325 14 G325R, G325R, G325E, G325W,
331 14
275 14 F275del,
322 15 T322M, T322A, T322K,
329 15 A329T,
270 15 F270S,
234 15 Q234H, Q234H,
319 15 V319L, V319L,
310 15 V310I,
272 15 G272D, G272S, G272V,
321 15